KR19980024535A - Gas analysis device and gas analysis method - Google Patents

Abstract

The present invention uses a gas analysis device and a gas analysis device used for pollution control in a clean environment by collecting samples from these points while switching a plurality of measurement points and continuously monitoring the volatile components present in the ambient air. It is about a method. The analytical device does not require an increase in the number of parts and can have a good response in a short measuring period.

The gas analyzer of the present invention has two gas sampling units. Each solution transfer pump 3, 15 is operated for a different diffusion scrubber. The diffusion scrubber connected to the solution transfer pump 15 is placed in a measurement state, and the analytical gas component absorbed in the absorbing solution in the diffusion scrubber is captured by the concentration column 14 and analyzed by the ion chromatograph 30. During this cycle a preliminary operation is carried out in parallel with the other diffusion scrubber connected to the solution transfer pump 3. Therefore, the adverse effect of the previous analysis due to the memory effect is prevented, the response is improved, and the measurement cycle is shortened.

Description

Gas analysis device and gas analysis method

The present invention relates to a gas analysis device that switches over a plurality of points in a clean environment, collects samples therefrom, continuously monitors volatile components in the air, and controls contamination of the clean environment, and a gas analysis method using the gas analysis device. .

Recently, a gas analysis device using a diffusion scrubber that absorbs a water-soluble gas component in a sample gas as an absorption solution has been developed, for example, in January 1989, Analytical Chemistry, Vol. 61, No. 1 ( Analytical Chemistry, VOL. 61, NO. 1) or Japanese Patent Application Laid-open No. Hei 8-54380. Gas analysis method using such a gas analyzer has a sampling time of 1/5 to 1/10 is sufficient compared to the method of analyzing ammonia or acid gas in gas by impinger sampling, which has been used for a long time, and has a one hour on-site. Since automatic measurement can be performed within the measurement cycle, it is effective for monitoring when the concentration of ammonia and acid gas in the production environment must be strictly controlled. 8 shows a gas analyzer of Japanese Patent Laid-Open No. 8-54380 in which a sampling unit based on a diffusion scrubber and an ion chromatograph are combined. In the gas analyzer of Fig. 8, the diffusion scrubber body 10 is composed of an inner tube 4 of a gas permeable membrane tube and an outer tube 5 into which the inner tube is inserted. The absorbent solution flows from the inlet 6 into the diffusion scrubber and out of the outlet 7. While continuously absorbing the sample gas by the sampling pump while continuously passing the absorbent solution through the gap between the outer tube and the inner tube and continuously passing the gas inside the inner tube, the analytical gas component in the gas is absorbed into the absorbent solution in the diffusion scrubber. Is absorbed. The analytical gas component is captured in the concentration column and concentrated by passing the absorption solution absorbing the analyte gas components through the concentration column 14. The analysis steps using the gas analysis device include the following steps in that order.

(1) a preliminary step of bringing the analytical gas component in the sample gas into parallel with the analytical gas component in the absorbent solution,

(2) after the preliminary step (1), a washing step of washing the extract solution component remaining in the concentrated column with pure water;

(3) after the washing step (2), a sampling step of concentrating the analyte gas component by introducing an absorption solution absorbing the analyte gas component from the diffusion scrubber into a concentration column;

(4) After the sampling step (3), an analysis step of extracting the analysis gas component trapped in the concentrated column and separating it by ion chromatography.

Although it is due to the characteristic of the diffusion scrubber used, especially the gas permeable membrane tube, when the density | concentration of the analyte gas component in a sample gas changes suddenly by the memory effect of a diffusion scrubber, the analysis result immediately after a concentration change becomes inaccurate. In the analysis apparatus disclosed in Japanese Patent Laid-Open No. 8-54380, the preliminary step (1) is performed prior to the sampling step (3), thereby minimizing the memory effect (the adverse effect of the previous analysis).

However, in analyzing the specific component of the gas by switching the sampling point (measurement point) of the gas, a change in concentration of the specific component by switching occurs. Therefore, it is necessary to make the preliminary operation time long enough, or to take a method of making the last measurement measured in actual concentration in several successive measurements. Therefore, only 20 minutes are needed for measuring one sampling point when the measurement is made multiple times, but if the measurement is made by switching the sampling points, the time required for measuring one sampling point is about one hour. Done. In Japanese Patent Laid-Open No. Hei 8-54380, there is also disclosed a gas analyzing apparatus used for gas analysis for switching a plurality of sampling points, in which two lines other than an ion chromatograph are provided. However, the gas analyzer has a large number of parts, which inevitably increases the size of the apparatus and increases the manufacturing cost.

An object of the present invention is to collect a sample therefrom while switching a plurality of points, to continuously monitor the volatile components in the atmosphere, to be used for pollution control in a clean environment, to suppress an increase in the number of parts of an analytical device, and at the same time to achieve a short measurement cycle. The present invention provides a gas analyzing apparatus capable of obtaining responsiveness and a gas analyzing method using the gas analyzing apparatus.

1 is a schematic diagram showing an overall configuration of an embodiment of a gas analyzing apparatus of the present invention.

2 is an operational flowchart of an analysis step by the gas analysis device of FIG.

FIG. 3 is a flowchart showing the flow of measurement condition setting used when performing the operation sequence of FIG. 2; FIG.

FIG. 4 is a schematic diagram of a screen (used for setting measurement measurement conditions) of the control unit of the gas analyzer of FIG. 1 (the control unit is not shown in FIG. 1).

Fig. 5 is a schematic diagram showing the overall configuration of another embodiment of a gas analyzing apparatus of the present invention.

6 is an operational flowchart of an analysis step by the gas analysis device of FIG.

FIG. 7 is a flowchart showing a flow of measurement condition setting used when performing the operation sequence of FIG. 6; FIG.

8 is a schematic diagram showing an overall configuration of a conventional gas analyzer.

Explanation of symbols for the main parts of the drawings

2: flow path switching valve

3: transfer pump

11: flow path switching valve

15: transfer pump

4: inner tube

5: outer tube

6: inlet

7: outlet

10: diffusion scrubber body

12: sampling pump

20: diffusion scrubber body

22: sampling pump

13, 13a, 13b: intake vent

14: concentrated column

23, 23a, 23b: intake vent

30: ion chromatograph

33: separation column

35: conductivity detector

36: storage container

41: storage container

51: flow path switching valve

52: flow path switching valve

The above object of the present invention is achieved by the use of various means for increasing the operating efficiency of the gas analyzer and shortening the measurement cycle of the gas analyzer.

According to the present invention, the concentration of gaseous contaminants present in the clean environment (eg clean room) of the manufacturing site can be controlled quickly and automatically. Therefore, the present invention is suitable for the clean control of the semiconductor manufacturing process environment and enables the increase of the reliability and the output of the device.

The present invention provides a gas analysis device used for analysis of an analyte gas component contained in a sample gas by absorption into an absorption solution. The gas analyzer includes two gas sampling units each including a tubular diffusion scrubber and a sampling pump, a solution transfer pump for supplying the absorbent solution into the diffusion scrubber of one gas sampling unit, and the absorbent solution into the diffusion scrubber of the other gas sampling unit. A solution transfer pump for feeding and leaving the diffusion scrubber into a concentration column filled with an adsorbent capable of concentrating the analyte gas component dissolved in the solution; a gas sampling unit connected to the former solution transfer pump; and a latter solution transfer pump. A flow path switching valve or device for switching the gas sampling units connected to each other, a detection unit for detecting analytical gas component captured by the concentration column, and a solution leaving the diffusion scrubber into a concentrated column for capturing and concentrating the analytical gas component To flow path to introduce and concentration column A flow path switching valve or device for switching the flow paths introducing the captured and concentrated analyte gas components into the detection unit with each other, each diffusion scrubber being provided inside the outer tube and the outer tube and containing the analytical gas component; An inner tube consisting of a gas permeable membrane capable of passing only a portion of the outer tube and the inner tube is secured by a pair of joints at its two ends, and the diffusion scrubber also communicates with the inner tube And at each end a port communicating with a gap between the outer tube and the inner tube, wherein either one of the inner tube of the inner tube and the gap between the outer tube and the inner tube is used as a passage of the absorbing solution, and the other of the sample gas Used as a passage, each sampling pump is connected to the passage for sample gas in the diffusion scrubber It is used to get into the diffusion scrubber.

The gas analyzer has a flow path switching valve for switching gas sampling points upstream of the gas inlet of each gas sampling unit.

The gas permeable membrane tube in the gas analysis device preferably has a porosity of 40 to 80%, a film thickness of 0.1 to 0.5 mm, and an immersion pressure of 0.2 kgf / cm ² or more.

The present invention also provides a gas analysis method using the above-described gas analysis apparatus and including the following steps a to c in that order.

To allow the analytical gas component in the sample gas to be in equilibrium with the analytical gas component in the absorbent solution, the absorbent solution and simultaneously the sample gas containing the analytical gas component are added to one of the sampling units. Step a and supplying,

Introducing b into the concentration column from the diffusion scrubber of the gas sampling unit by use of another solution transfer pump;

Extracting the analyte gas component captured by the concentration column after step b and analyzing it by the detection unit c.

In the above method, step a and c are performed on the sample gas taken into one gas sampling unit, while step a is performed on the gas sample taken into another gas sampling unit.

The present invention also provides a control unit capable of performing the above-described gas analysis method and calculating the time of steps a to c based on the value input as the minimum required time required for steps a to c and the value input as the desired measurement period. It provides a gas analysis device having.

In the above-described gas analysis method, it is preferable that step b begins for the sample gas taken into another gas sampling unit as soon as step c is completed for the sample gas taken into one gas sampling unit.

Also in the above-described gas analysis method, as soon as step b is completed for the sample gas taken into one gas sampling unit, step a for the next cycle is started in the gas sampling unit and this step a is taken into the other gas sampling unit. It is preferred to complete as soon as step c is complete for the gas.

A first embodiment of the present invention is described with reference to a part of the accompanying drawings. FIG. 1 schematically shows the overall configuration of a first embodiment of a gas analyzing apparatus of the present invention, FIG. 2 shows an operation sequence of analysis steps performed when the gas analyzing apparatus of FIG. 1 is used, and FIG. 4 is a flowchart showing a measurement condition setting process used in the execution of the operation sequence, and FIG. 4 is a schematic diagram of a screen (used for setting the measurement condition) of the control unit (not shown in FIG. 1) of the gas analyzing apparatus of FIG. .

In Fig. 1, A and B of the diffusion scrubber main body 20 are connected to A and B of the flow path switching valve 2, respectively. In Fig. 2, ①-1 and ①-2 are the first and second measurements of the gas collected from the intake port 13, respectively. ②-1 and ②-2 are the 1st and 2nd measurement of the gas collected from the intake port 23, respectively. For each measurement, a, b and c represent the respective stages of preliminary operation, sampling and separation analysis, respectively. In Fig. 2, all the preliminary operation times are the same, but the preliminary operation time may be extended for ②-1. For example, step a of ①-1 and ②-1 may be started simultaneously.

The "solid line" and the "broken line" of the flow path switching valves 2 and 11 in FIG. 2 correspond to the switching state of each valve in FIG. The absorbent solution conveyed by the solution transfer pump 15 flows through the diffusion scrubber body 10 when the flow path switching valve 2 is set to the solid line state, and the flow path switching valve 2 is set to the broken line state. When there is, it flows through the diffusion scrubber body 20. The absorbent solution conveyed by the solution transfer pump 3 flows through the diffusion scrubber on the other side separately from the diffusion scrubber which the absorbent solution conveyed by the solution transfer pump 15 flows through. When the flow path switching valve 11 is in the broken state, the solution from the diffusion scrubber is introduced into the concentration column 14, and the gas to be analyzed in the solution is captured by the column 14. When the flow path switching valve 11 is in the solid line state, preliminary operation and separation / analysis are performed. That is, in one flow path, the analysis target gas component captured by the concentration column 14 is extracted by the extract liquid sent from the storage tank 36 and transferred to the separation column 33. At this time, the other flow path is used for the preliminary operation. After the start of the preliminary operation of the first measurement, both the diffusion scrubber main bodies 10 and 20 always distribute the absorbing solution and the sample gas, and the diffusion scrubber not set for sampling is always used for the preliminary operation.

In Fig. 1, each intake port of the diffusion scrubber body 10, 20 is provided below the main body, but the positions of the intake port and the diffusion scrubber body are not limited to those shown in Fig. 1. In order to always fill the absorption solution flow path in a diffusion scrubber with an absorption solution, it is preferable to install a diffusion scrubber main body perpendicularly | vertically so that an intake port may be over a main body.

The gas permeable membrane tubes constituting each of the diffusion scrubber bodies 10 and 20 have a porosity of 40% or more and 80% or less, and a membrane thickness of 0.1 mm or more and 0.5 mm or less, on which the immersion pressure (membrane across the membrane) is placed. When the gas is placed on the water and the other side, and the pressure is applied to the water, the threshold pressure at which water does not leak out to the gas side) is preferably 0.2 kgf / cm 2 or more. The thinner the film thickness, the smaller the memory effect and the larger the porosity, the higher the collection efficiency. The film thickness is preferably 0.1 mm or more and 0.3 mm or less, and more preferably 50% or more and 80% or less.

The timetable for each analysis step is shown in FIG. The time setting of each analysis step is not limited to this, and sampling and separation / analysis at one sampling point and sampling and separation / analysis at another sampling point may not occur at the same time. If the time table is set so that (measuring cycle) = 2 * (sampling time + separation / analysis time), the above conditions can be satisfied, and the ion chromatograph can be operated most efficiently. In order to perform continuous autonomous operation, the timetable should also be (preliminary operation time) ≥ (sampling time + separation / analysis time) and allow the initiation of preliminary operation to be after the start of the separation analysis of the previous measurement in the same diffusion scrubber. It is necessary to set. The timetable of each analysis step when using the analysis device of FIG. 1 is set up according to the flowchart of FIG. The minimum allowable value other than the minimum allowable value Pmin of the measurement period is displayed on the measurement condition setting screen (not shown) by prior input. The measurer inputs the sampling time T2 into the T2 space of FIG. 4 in consideration of the concentration of the analytical gas component at the sampling point and the minimum allowable value T2 min of sampling. When a T2 value larger than T2min is input, the measurement period minimum allowable value Pmin calculated from the value of T2 and the value of T3min is displayed in the Pmin display space of the measurement condition setting screen. When the measurer inputs the measurement period P in consideration of Pmin, the preliminary operation time T1, the separation analysis time T3, and the delay time D are calculated. Delay time (D) is the time difference between the analysis using one gas sampling unit and the analysis using the other gas sampling unit; For example, it is the difference of the start time of step a of ①-2 and ②-2 in FIG. If T3 and T1 are less than the minimum allowable value, P input is required again. When gas analysis is performed on the basis of the calculated conditions as described above, for example, 30 minutes after the start of operation as shown in FIG. 2, the ion chromatograph mechanically repeats sampling and separation / analysis so that efficient measurement can be performed. .

Example 1

Next, Example 1 of this invention is demonstrated in detail with reference to drawings. In the gas analyzer of Fig. 1, a separation column 33 (Dionex Corporation, Ion Pac CS 12), a concentration column 14 (Dionex, Ion Pac CG 12), and conductivity Ion chromatograph 30 (Dioex, manufactured by Dionex Co., Ltd., CSRS-I) connected between detector 35 and separation column 33 and conductivity detector 35 The case of ammonia analysis in gas using Nex Corporation make DX100) as a detection unit of an analysis apparatus is demonstrated. Extremely pure water as an absorbent solution is placed in the storage container 41, and a 20 mM methylsulfonic acid solution is put in the storage container 36 as an extract. Each of the diffusion scrubber main bodies 10 and 20 has an inner tube of a fluorine resin gas permeable membrane tube (Sumitomo Electric Industries, Poreflon tube) having a film thickness of 0.3 mm and an inner diameter of 2 mm, and a fluorine resin tube (inner diameter of 10 mm, What consisted of the outer tube of 12 mm of outer diameters was used. As the solution transfer pump 15, a pump having a discharge pressure capable of easily introducing the absorbent solution into the concentration column 14 is used. In the case of the concentration column (Dionex, Ion Pac CG 12), the discharge pressure is required 30 kgf / cm 2 or more, preferably 50 kgf / cm 2 or more. It is preferable that the discharge pressure of the solution transfer pump 3 is several kgf / cm 2, and a cheaper one can be used than the pump 15. The flow rates of the solution transfer pump 36 were set to 1.0 ml / min, and the flow rates of the solution transfer pumps 3 and 15 were set to 2.0 ml / min. In consideration of the collection performance of the diffusion scrubber, the flow rates of the sampling pumps 12 and 22 were set to 0.5 l / min. When the ion chromatograph 30 is operated under the above conditions, ammonia is extracted in approximately 4.5 minutes, but it takes about 9 minutes for separation analysis to completely extract the alkaline earth metal component. Therefore, the minimum allowable separation assay (T3min) was 10 minutes. The minimum allowable value (T1min) of the preliminary operation time was set to 20 minutes in consideration of the memory effect in the diffusion scrubber. Since the ion chromatograph can fully quantify ammonia if it is about 0.1 ng as an absolute amount, the sampling time T2 is set to 10 minutes in the operational flowchart of the analysis step of FIG. When T2 is input in accordance with the flowchart of Fig. 3, the measurement period minimum allowable value Pmin is calculated and displayed as 40 minutes. Next, as a result of inputting the value of Pmin into the analysis period P, as shown in Fig. 2, the preliminary operation time was 30 minutes, the separation analysis time was 10 minutes, and the delay time D was 20 minutes. When measurement was performed by this setting, first analysis data of two sampling points was obtained 50 minutes and 70 minutes after the start of measurement, and analysis data could be obtained every 40 minutes thereafter.

Example 2

Next, Example 2 of the present invention will be described with reference to the drawings. In Example 1 above, a gas analyzer that can measure these points while switching between two sampling points has been described. In the present embodiment, a gas analysis apparatus capable of performing measurement while switching more and more points, for example, four sampling points, will be described. FIG. 5 is an overall configuration diagram of a second embodiment of the gas analyzing apparatus of the present invention, FIG. 6 is an operational flowchart of analysis steps employed in the use of the gas analyzing apparatus of FIG. 5, and FIG. 7 is used to perform the operating sequence of FIG. It is a flow chart showing a measurement condition setting procedure.

In Fig. 5, A and B of the diffusion scrubber main body 20 are connected to A and B of the flow path switching valve 2, respectively. In Fig. 6, ①-1 is from the inlet port 13a, ②-1 is from the inlet port 23a, ③-1 is from the inlet port 13b, and ④-1 is from the inlet port 23b. The first measurement is shown. In addition, -2 means the 2nd measurement, (1) -2 shows the 2nd measurement of the gas collected from the intake port 13a. For each measurement, a, b and c represent the respective stages of preliminary operation, sampling and separation analysis, respectively.

The "solid line" and the "broken line" of the flow path switching valves 2, 11, 51, and 52 in FIG. 6 correspond to the switching state of each valve in FIG. The absorbent solution conveyed by the solution transfer pump 15 flows through the diffusion scrubber 10 when the flow path switching valve 2 is set to the solid line state, and the flow path switching valve 2 is set to the broken line state. At this time, it flows through the diffusion scrubber 20. The absorbent solution conveyed by the solution transfer pump 3 flows through the diffusion scrubber on the other side separate from the diffusion scrubber through which the absorbent solution conveyed by the solution transfer pump 15 flows.

When the flow path switching valve 11 is in the broken state, the solution from the diffusion scrubber is introduced into the concentration column 14 so that the gas component to be analyzed in the solution is captured by the column 14. When the flow path switching valve 11 is in the solid line state, preliminary operation and separation / analysis are performed. That is, in one flow path, the analysis target gas component captured by the concentration column 14 is extracted by the extraction liquid sent from the storage tank 36 and transferred to the separation column 33. At this time, the other flow path is used for the preliminary operation. Each diffusion scrubber body (10, 20) always flows through the absorbent solution and sample gas taken from one sampling point after the start of the preliminary operation of each first measurement (①-1 and ②-1), and is not used for sampling. Diffusion scrubbers are always used for reserve operation.

The timetable of each analysis step is shown in FIG. The timetable of each analysis step is not limited to this, and the sampling and separation analysis at one sampling point and the sampling and separation analysis at another sampling point do not occur at the same time, and change from the hinge point to another point for each diffusion scrubber. It can be any value as long as it does not occur until sampling at this point is complete. In order to perform continuous automatic operation it is also necessary to set the timetable of the analysis process so that (preliminary operation time) ≥ (sampling time + separation analysis time). Specifically, as shown in FIG. 6, the start of preliminary operation of ③-1 starts after the separation analysis start of ①-1, and the completion of sampling of ②-1 becomes after completion of the separation analysis of ①-1 (hereinafter, the same). In each case, a switchover of each analysis step should be performed. If the timetable is set as shown in Fig. 6, 30 minutes after the start of the measurement, the ion chromatograph may repeat the sampling and separation analysis mechanically to perform efficient measurement. In addition, as long as the above conditions are satisfied, the preliminary operation time can be extended and shortened.

In the practice of this example, a gas analyzer capable of measuring the points by switching the four sample rim points was described. The gas analysis apparatus, which is capable of measuring more sampling points by switching those points, uses flow path switching valves each having a switching function of three or more sampling points instead of the paid switching valves 51 and 52, It can be easily manufactured by setting an operation flowchart that satisfies the aforementioned measurement conditions.

Example 3

Next, Example 3 of the present invention will be described in detail with reference to the drawings. Referring to Fig. 5, the case where the same one described in Example 1 above is used for the ion chromatograph, the diffusion scrubber, the solution transfer pump, and the sampling pump will be described. The minimum allowable value (T3min) of the separation analysis time was set to 10 minutes, and the minimum allowable value (T1min) of the preliminary operation time was set to 20 minutes. In addition, the sampling time T2 in the operation flowchart of the analysis step of FIG. 5 was set to 10 minutes. When T2 is input in accordance with the flowchart of Fig. 7, the measurement period minimum allowable value Pmin is calculated to be 80 minutes. As a result of setting this value Pmin to the measurement period P2, the preliminary operation time T1 became 30 minutes, the separation analysis time T3 became 10 minutes, and the delay time D became 20 minutes. When the measurement is performed by this setting, the first analysis data is obtained at 50 sampling points, 70 minutes, 90 minutes, and 110 minutes from the start of measurement at the sampling points ①, ②, ③, and ④, respectively. Analytical data at the point could be obtained.

As described above, according to the present invention, concentration control of gaseous pollutants in a clean manufacturing environment such as a clean room can be performed quickly and automatically. Therefore, it is very suitable for the cleanliness management of the environment of the semiconductor manufacturing process, and by applying it to the cleanliness management, it is possible to improve the reliability and production yield of the device.

Claims (7)

A gas analysis device used for analysis of an analytical gas component contained in a sample gas by absorption into an absorption solution, Two gas sampling units each comprising a tubular diffusion scrubber and a sampling pump, A solution transfer pump for supplying the absorbent solution into the diffusion scrubber of one gas sampling unit, A solution transfer pump which feeds the absorbent solution into the diffusion scrubber of another gas sampling unit and introduces the solution leaving the diffusion scrubber into a concentrated column filled with an adsorbent capable of concentrating the analyte gas component dissolved in the solution; A flow path switching valve or device for switching between a gas sampling unit connected to the former solution transfer pump and a gas sampling unit connected to the latter solution transfer pump; A detection unit for detecting an analyte gas component captured by the concentration column; A flow path switching valve or device for switching a flow path for introducing a solution leaving the diffusion scrubber into a concentration column for capturing and concentrating an analytical gas component and a flow path for introducing an analyte gas component captured and concentrated by the concentration column into a detection unit; Including, Each diffusion scrubber comprises an inner tube consisting of an outer tube and a gas permeable membrane provided inside the outer tube and capable of passing only a portion of the sample gas containing the analytical gas component, the outer tube and the inner tube being the two. Secured by a pair of joints at the two ends, the diffusion scrubber also includes at each end a port in communication with the inner tube and a port in communication with a gap between the outer tube and the inner tube, the inner and outer tubes of the inner tube and One of the gaps between the inner tubes is used as the passage of the absorbent solution, the other as the passage of the sample gas, and each sampling pump is connected to the passage for the sample gas of the diffusion scrubber and to bring the sample gas into the diffusion scrubber. Gas analysis device, characterized in that used. 2. The gas analyzer of claim 1, wherein a flow path switching valve for switching gas sampling points is provided upstream of the gas inlet of each gas sampling unit. The gas analyzer of claim 1, wherein the gas permeable membrane tube has a porosity of 40 to 80%, a film thickness of 0.1 to 0.5 mm, and a immersion pressure of 0.2 kgf / cm ² or more. The method of claim 1, further comprising performing a gas analysis method comprising the following steps a to c in order, and based on the value input as the minimum required time required for steps a to c and the value input as the desired measurement period. and a control unit capable of automatically calculating the times a to c. Supplying one of the sampling units with the absorbent solution and simultaneously with the sample gas containing the analyte gas component by means of a solution transfer pump such that the analytical gas component reaches an equilibrium between the absorbent solution and the sample gas. with a, Introducing b into the concentration column from the diffusion scrubber of the gas sampling unit by use of another solution transfer pump; Extracting the analyte gas component captured by the concentration column after step b and analyzing it by the detection unit c. In the above method, while step b and step c are performed on the sample gas taken into one gas sampling unit, step a is performed on the gas sample taken into another gas sampling unit and step b for the sample gas taken into the gas sampling unit As soon as is performed, step a for the next cycle is started in the gas sampling unit, and this step a is completed as soon as step c is completed for the sample gas taken into another gas sampling unit. A gas analysis method comprising using the gas analysis device according to any one of claims 1 to 3 and including the following steps a to c in that order. To allow the analytical gas component in the sample gas to be in equilibrium with the analytical gas component in the absorbent solution, the absorbent solution and simultaneously the sample gas containing the analytical gas component are added to one of the sampling units. Step a and supplying, Introducing b into the concentration column from the diffusion scrubber of the gas sampling unit by use of another solution transfer pump; Extracting the analyte gas component captured by the concentration column after step b and analyzing it by the detection unit c. In the above method, step a and c are performed on the sample gas taken into one gas sampling unit, while step a is performed on the gas sample taken into another gas sampling unit. 6. The method of claim 5, wherein as soon as step c is completed for the sample gas taken into one gas sampling unit, step b begins for the sample gas taken into another gas sampling unit. 6. The method of claim 5, wherein as soon as step b is completed for a sample gas taken into one gas sampling unit, step a for the next cycle begins in the gas sampling unit, which step a takes into account the sample gas taken into another gas sampling unit. Gas analysis is completed as soon as step c is completed.